Fuse switch



Dec. 14, 1937. T. BIRKENMAIER FUSE SWITCH Filed May 18, 1935 3 Sheets-Sheet l FIGI.

Dec. 14, 1937. T. BlRKENMMER FUSE SWITCH Filed May 18, 1935 3 Sheets-Sheet 2 FIG-.2.

Dec. 14, 1937. T. BIRKENMAIER FUSE SWITCH- Filed May 18, 1955 3 Sheets-Sheet 3 Patented Dec. 14, 1937 UNITED STATES PATENT OFFICE FUSE SWITCH Application May 18, 1935, Serial No. 22,139

I Claims. (01. 200-128) This invention relates to fuse switches, and withregard to certain more specific features, to fuse switches for repeatedly fusing a circuit.

This invention is an improvement upon the construction shown in United States Patent 1,993,083, issued to Lester P. Boll, on March 5. 1935.

Among the several objects of the invention may be noted the provision of an improved attachment of the class set forth in said patent, which has a fast, trigger-released switch closing action, set off by theopening action of -a fuse unit, but which is independent of the characteristic opening movement of said unit; the provision of apparatus of the class described in which the switch closing movement is not only independent of the character of the fuse unit opening movement but which has a snap action; .the provision-of apparatus of this class which permits a fast initial opening of the fuse unit with minimum interference thereto by switch operation; the provision of means for reopening of said switch by the closing action of the fuse unit with minimum resistance; and the provision of ap;

g paratus of the class described which shall be simple in construction and operation. Other objects will be in partobvious and in part pointed out hereinafter.

The invention accordingly comprises the eleo ments and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

5 In the accompanying drawings, in which is illustrated two of various possible embodiments of the invention,

Fig. 1 is a front elevation showing the attachment applied between two fuse switches;

40 Fig. 2 is a side elevation of Fig. 1;

Fig. 3 is a vertical section taken on line 3-3 of Fig. 1;

Fig.- 4 is a section taken on line 4-4 of Fig. 2;

Fig. 5 is a side elevation, on a reduced scale,

45 showing an incipient opening action of a fuse unit;

Fig. 6 is a fragmentary front elevation showing in detail the positions of certain parts of, the incipiently moving fuse unit A of Fig. 5;

50 Fig. 'l is a view similar to Fig. 6 but showing a subsequent positioning of parts while in motion, and,

Fig. 8 is a view similar to Fig. 6, showing a final position of parts.

55 Similar reference characters indicate corresponding parts throughout the several views of the drawings.

As was the case in the construction of the fuse switch shown in said Patent 1,993,083, the present invention also permits the use of known fuse 5 switches in multiple as reclosure switches without the necessity of the user purchasing complicated apparatus; With the present attachment,

a given fuse switch may be used either as a single, non-reclosing switch, or may be used in 10 combination with other like switches in a reclosing combination. Furthermore, as many reclosures as may be desired may be effected without increasing complications, merely by applying as many of applicants attachments as there are 15 desired reclosure switches.

Referringnaw more particularly to Fig. i, there is shown atnumeral I a support for brackets I which holdfuse switches A and B. The fuse switches A-and B, per se, are of known types and 20 comprise insulators i supporting upper and lower brackets 1 and 0 respectively. Connected to the upper brackets I is a line wire I] forming one side of a circuit. Connected to the lower bracket 9 of the left-hand switch A is a wire is leading to the other side of the circuit of which the wire Ii is a part.

Reaching from each upper bracket I is a line terminal spring assembly pivoted at l1 and normally held against a stop I! by means of a downwardly pulling tension spring 2|. An otfset, receased portion 23 of the spring assembly I5 is adapted to receive lateral gudgeons 25 of a terminal engaging element 21 of a fuse tube or cartridge 29. Each cartridge 28 also has a lower terminal engaging element 3i pivoted at 13 to a ring 35 fastened around the cartridge 29.

Associated with the ring 35 is an eye 34 for effecting manipulations in applying and removing the cartridge. Associated with the upper line terminal engaging element 21, is an eye 28 for cooperation with a tool used for opening and closing the cartridge.

A fuse link 31 normally holds the pivoted terminal 3| rigidly against the cartridge 29 and also serves to effect an electrical connection between said terminal engaging elements 21 and II. This rigidly spaces gudgeons 25 and 39, the latter being on said hinged element 3!.

The fuse link 31 is fastened to the lower terminal engaging element II in a novel manner. This is accomplished by providing a lug 2 under which is an open notch 4. Through the lug 2 is threaded a thumbscrew 8. The juncture between the lug 2 and the terminal engaging element Si is formed with snubbin'g edges 8 (Fig. 4) over' one of which the fuselink 31 is snubbed, prior to fastening and screwing down the screw 6 to frictionally hold the same. The respective snubbing edge 8 over which the fuse link 31 is snubbed, functions toreduce the amount of strain of the tensioned link delivered to the frictional hold beneath the screw 6. Thus, there is substantially no danger of the fastenings being loosened by the tension in the fuse link.

The gudgeons 39 are applicable to recesses 4| in extensions from said lower. bracket 9 and are removable from the recesses 4| for effecting refusing of the cartridge 29. When the fuse 31 blows, rotation takes place at 33 and 39 (see Fig. 5) and the cartridge descends, first under pressure from the spring assembly l5 and then by gravity. The cartridge 29 thereafter rotates clockwise from the position shown in Fig. 5, to the depending position shown in Fig. 8, passing through the various positions shown .in Figs. 5 to '7. It is then removed from the bracket for refusing and is then returned to the bracket to be again swung into place.

I The attachment per se consists of a bracket 43 which is adapted to be bolted to any one of said lower brackets 9 of the fuse switch A or B, or any other similar ones. This bracket 43 supports an insulator 41. On the outer end of the insulator is a support 49 for a spring contact 5|. The support 49 and the contact 5| are electrically conductive but are insulated from the bracket 43 by the insulator 41. An electrical connection 53 is provided for the reception of a wire 55 which leads to the corresponding bracket 9 of the second fuse switch B.

The bracket 43 rotatably supports at center 46 a spider 45 which has a finger 51 lying behind and gravitationally against the cartridge 29 and also a forwardly extending finger 59 (Fig. 3).

The bracket 43 also carries a headed gudgeon 6| for rotatably supporting two elements, nameLv, an over-centering switch blade 63, and a cooperating trigger 65. The Switchblade 63 has a contact face 61 which, when the switch is closed, cooperates with the spring contact 5| to close the circuit between wires I and I3 through the second switch B.

The switch blade'63 is normally held open by means of the spring H reacting from an arm 69 fastened to the bracket 43. In open position, the reaction between the point of fastening of the spring H with the arm 69 on the one hand, and its connection 13 with the arm 63 on the other hand, lies below the center of the gudgeon 6|, so that the switch is held open.

The switch blade 63 carries an arcuate lug 15, which, with lost motion fits within a recess 11 of the trigger 65. The trigger 65 is also rotatable on the gudgeon 6| and has an extending operating finger 8|. The trigger finger is freely rotatable to a degree permitted by the lost motion. It is normally held in an upward position (Figs. 1, 2 and 3) by means of said finger 59 of the spider .45. Spider 45 is held in its upward position by the holding action of the closed cartridge 29 on the finger 51.

As shown in Figs. 1 to 3, with an unbroken fuse 31 in the cartridge 29, and a closed condition of the cartridge, the cartridge holds up the spider 45bry contact with the finger 51 which in turn holds up the finger 59 so as to hold up the trigger 'finger 8|. 'This'places lost motion between the trigger body 65 and the arcuate lug 15 of the switch blade 63 (Fig. 1). The switch blade 63 is prevented from being drawn further open by the spring H, because of the action of a stop 83 on the blade 63 acting against an extension 84 from the bracket 43.

When the fuse link 31 is overloaded by a current flowing from one side II to the other side I3 of the circuit, it blows, thus permitting rotation of the cartridge 29 at the centers 33 and 39. The cartridge 29 falls through the position shown in Fig. 5. In descending, the finger 59 is permitted to descend, the finger 51 gravitationally following behind the cartridge 29. This places the trigger 8| which rests on finger 59 in the path of the descending eye 34, and if an eye such as 34 is not used, then in the path of the cartridge 29 per .se. In so positioning the finger 8|, the clearance between the notch 11 and lug I5 is taken up (see Fig. 6). Thus the trigger is instantly set for operation. So far, no interference has been established with the falling of the cartridge.

As the cartridge falls, it and the eye 34 gain momentum and the latter strikes the trigger finger 8| which instantaneously moves the switch blade-63 counterclockwise and immediately positions the line of reaction of the spring 1| above the center of the gudgeon 6|. This action may be made quite critical, so that just a touch of the falling cartridge parts on the trigger finger 8| will set off the spring II to snap shut the switch. Fig. 7 shows the condition of parts just'subsequent to the eye 34 having struck the trigger finger 8|. It will be-seen that there was only a slight period of contact during which the switch blade was set off by the action of the cartridge, and thereafter the spring effected actual switch closure.

Finally, the finger-8| gravitates to the dottedline position shown in Fig. '7 (solid-line position in Fig. 8) to introduce lost motion in the reverse direction of rotation, between the notch. 11 and the lug l5.

Upon the cartridge 29 assuming the depending position shown in the Fig. 8, it may be removed, the gudgeon 39 being taken from the recesses 4|.

Unlike certain other reclosing switches, the

switch 63, 5| is not locked shut and may be reopened at anytime by merely depressing the same with a suitable tool. And, to reclose it manually, it may be merely pushed shut and the spring 69 will'over-center to function. No locks need to be manipulated.

If that which caused the blowing of the'fuse' unit A does not clear the line, the second fuse unit B will blow after the switch 63, 5| closes. The inherent time lag in closing the switch'63, 5| usually permits trouble on the line to clear. If this time lag is found not great enough, then a similar switch attachment may be applied to the switch B, and another fuse switch placed across the line and fed current by said added switch unit when the preceding fuse unit blows. The number of attachments used, and added fuse switches, is indefinite.

After blowing of one or more of the fuse units, taking-the fuse unit A for example, the cartridge is refused to again make it rigid, the gudgeons 39 are reapplied to the recesses 4| and the cartridge is swung from the position shown in Fig. 8 back to that shown in Fig. 2. In this process, the finger 51 behind the tube 29 is raised, thus to raise the finger 59 of the spider 45. Inasmuch as the trigger finger 8| is in the path of said lifting finger 59 (Fig. 8) said trigger will be rotated clockwise to take up the clearance above the lug I5. Ultimately, the rotation of the trigger member 65 causes rotation of the switch blade 63 (clockwise), until the spring H is again over-centered to a position below the center of the gudgeon 8|. This reopens the switch 63, 5| and the amount of clearance introduced by the over-centering due to reopening provides means for further lifting of the trigger finger 8| by the lifting finger 59 so that the trigger finger 8| is entirely clear of the cartridge unit (see Fig. 1).

Among the advantages of the invention is the fact that the fuse cartridge 29 has practically a free fall except for the slight touch required for setting off the trigger finger 8| and setting of! the spring H to effect closure of the switch blades 63. The design may be suited to very particular requirements, the trigger action being adapted to be made as sensitive as desired.

Furthermore, the actual switch closure operation is entirely independent of the weight of the cartridge per se. It is dependent primarily upon the characteristics of the spring II.

The device differentiates, among other ways, from former devices of the class, in that the tramfer switch for transferring the circuit from one fuse to the other is of the snap-acting variety, that is, its action is a discontinuous-fum tion of the action of the switch setting element.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a fuse switch having a cartridge movable upon blowing, an auxiliary switch, a blade for said auxiliary switch, resilient means normally over-centering said blade either to open or to closed position, a trigger mounted to drive the switch blade with lost motion to either overcentered position, and means for positioning said trigger to be actuated by the opening movement of the cartridge to set the switch to an overcentered position whereby said resilient means will effect closure thereof.

2. In a fuse switch having a cartridge movable upon blowing, an auxiliary switch, a blade for said auxiliary switch, resilient means normally over-centering said blade to open or to closed position, a trigger mounted to drive the switch blade with lost motion to either over-centered position, said trigger being adapted to be actuated by the opening movement of the cartridge to set the switch to an over-centered position whereby said resilient means will effect subsequent closure thereof.

3. In a fuse switch having a cartridge movable upon blowing, an auxiliary switch, a blade for said auxiliary switch, resilient means normally over-centering said blade to open or to closed position, a trigger mounted to drive the switch blade with lost motion to either overcentered position, positioning means for p04 sitioning said trigger to be actuated by the opening movement of the cartridge to set the switch to an over-centered position whereby said resilient means will effect closure thereof independently of further cartridge movement, and means for resetting the auxiliary switch to open position, said trigger to be engaged by said positioning means for resetting.

4. In a fuse switch having a cartridge movable upon blowing, an auxiliary switch, a blade for said auxiliary switch, resilient means normally over-centering said blade to open or to closed position, a trigger to drive the switch blade with lostmotion to either over-centered position, and means for positioning said trigger to be actuated by the opening movement of the cartridge to set the switch to an over-centered position whereby said resilient means will effect closure thereof, and to reset the switch to open position upon reclosure of the cartridge.

5. An attachment for fuse switches having line terminals and swingable cartridges, comprising a bracket adapted to be fastened to one line terminal adjacent the point of swinging of the cartridge, an insulator thereon, a contact carried by the insulator and electrically connected with another fuse switch, a switch blade pivoted to said bracket and normally insulated from said contact, an over-centering spiing adapted to hold said blade in either normally open position, or to move the same to engage said contact, and a trigger pivoted to said bracket and having a lostmotion engagement with said blade, a member pivoted to said bracket having means engageable with the cartridge whereby said member partakes of the cartridge-movement and having means engageable with said trigger, opening movement of the cartridge controlling said member to permit the trigger to be temporarily positioned to be engaged by the cartridge unit whereby the trigger is caused to over-center the switch blade,

said spring thereafter independently closing the blade against said contact.

6. An attachment for fuse switches having line terminals and swingable cartridges, comprising a bracket adapted to be fastened to one line terminal'adjacent the point of swinging of the cartridge, an insulator thereon, a contact carried by the insulator and electrically connected with another fuse switch, a switch blade pivoted to said bracket and normally insulated from said contact, an over-centering spring adapted to hold said blade in either normally open position, or to move the same to engage said contact, and a trigger pivoted to said bracket and having a lost-motion engagement with said blade, a member pivoted to said bracket having means engageable with the cartridge whereby said member partakes of the cartridge-movement and having means engageable with said trigger, opening movement of the cartridge controlling said member to permit the trigger to be temporarily positioned to be engaged by the cartridge unit whereby the trigger is caused to over-center the switch blade, said spring thereafter independently'closing the blade against said contact, and closing movement of the cartridge causing said member to reset the blade and trigger to open position.

7. An attachment for fuse switches having line terminals and swingable cartridges, comprising a bracket adapted to be fastened to one lineterminal adjacent the point of swinging of the cartridge, an insulator thereon, a contact carried by the insulator and adapted to be electrically connected with another one of said fuse switches, a switch blade pivoted to said bracket and normally insulated from said contact, an over-centering spring adapted to hold said switch in either normally open position, or to move the same' to engage said contact, a trigger pivoted to said bracket at the same center as the switch blade and having a lost-motion engagement with a portion of said blade, a spider pivoted to said bracket having means engageable with the.cartridge whereby the spider partakes 01' the cartridge movement, and having means engageable with said trigger, movement 01' the cartridge controlling said spider to permit the trigger to be temporarily positioned to be engaged by the cartridge whereby the trigger is caused to over-center the switch blade, said spring independently closing the blade, said means for setting the trigger being adapted to reset the same and to effect over-centering opening of the switch blade.

THEODORE BIRKENMAIER. 

